Check manual page of emcvnx_mirrorview

This check monitors the mirror view state and faulted state of
logical units such as disks or tape drives which are adressed
to a EMC VNX storage system by logical unit numbers (LUN).

The information is retrieved by the special agent agent_emcvnx which uses
EMC's command line tool naviseccli.

Only the active logical units are monitored.
The service states can be as following:
Active logical units are OK,
inactive ones are treated as CRIT and
logical units with the state 'Attention' are WARN.

Furthermore the faulted mirror view state can be:
- NO would be OK
- Yes would be CRIT.